Miniature electronic components are tested in a variety of ways. One group of testing that relates to multiple layer capacitance chips (MLCC) involves electrical testing, including, but not limited to cap testing, cross checking, testing for leakage current, and testing for break down voltage. In the example of U.S. Pat. No. 5,842,579 entitled Electrical Circuit Component Handler, which is incorporated herein by reference, there is shown an example of a rotary style electronic testing machine 10. With reference to FIG. 1 herein, which is a modification of FIG. 2 from U.S. Pat. No. 5,842,579, an electronic component is captured in a test plate 12. A vacuum source passes a vacuum through a base plate to draw electronic components into component pockets on test plate 12.
As illustrated in FIG. 2 herein a stepper motor 16 is operatively connected to test plate 12 to index test plate 12 such that electronic components are delivered to test heads 18 located on testing machine 10. Frequently the test heads are closely spaced. Each test head 18 may include a plurality of test contacts, each test contact configured to conduct the same test. After the testing is complete, test plate 12 continues to index to deliver tested components to blow off zone 22. In blow off zone 22 the electronic components are blown out of the component pocket that contains them and appropriately sorted as a function of the test results. In the example of U.S. Pat. No. 5,842,579 the blow off is accomplished by passing the component pockets over a plurality of blow off holes such that actuation of an air source through a specific blow off hole operates to sort the electronic components according to their individual test results.
Other configurations of test machines are also available. For example, the test plate, rather than being circular in shape may be rectangular. Also drums may be used for certain testing arrangements.
Electronic component testers may be adjusted and/or calibrated such that the individual test contacts properly align over component pockets such that when the test plate 12 is indexed the electronic components are delivered to the contacts so that an acceptable electrical connection is achieved. One way to align the test contacts with the test component pockets is the use of a fixture to assist the placement of test heads. Proper alignment can be more accurately realized by checking the alignment of the test heads with a borescope. In particular, the borescope would be used to visually inspect each contact and its relative positioning against the component pockets on the test plate. This evaluation would include inspection of theta and skew. If a determination was made that the test contact or test head was misaligned, alignment could be achieved by known adjustments.
Because the test heads may be closely spaced, use of borescope may be difficult and time consuming. A need has arisen to improve the process of determining the alignment of the contact heads.